[src/trunk]: src/sys Ensure that you can only bind a more specific address wh...

[lukem <lukem%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/fd1205af3b61
branches:  trunk
changeset: 467339:fd1205af3b61
user:      lukem <lukem%NetBSD.org@localhost>
date:      Tue Mar 23 10:45:37 1999 +0000

description:
Ensure that you can only bind a more specific address when it is done by the
same uid or by root.

This code is from FreeBSD. (Whilst it was originally obtained from OpenBSD,
FreeBSD fixed it to work with multicast. To quote the commit message:
    - Don't bother checking for conflicting sockets if we're binding to a
      multicast address.
    - Don't return an error if we're binding to INADDR_ANY, the conflicting
      socket is bound to INADDR_ANY, and the conflicting socket has
      SO_REUSEPORT set.
)

diffstat:

 sys/kern/uipc_socket.c  |   4 +++-
 sys/kern/uipc_socket2.c |   3 ++-
 sys/netinet/in_pcb.c    |  17 ++++++++++++++++-
 sys/sys/socketvar.h     |   4 ++--
 4 files changed, 23 insertions(+), 5 deletions(-)

diffs (84 lines):

diff -r fd7d8b34272c -r fd1205af3b61 sys/kern/uipc_socket.c
--- a/sys/kern/uipc_socket.c    Tue Mar 23 10:22:31 1999 +0000
+++ b/sys/kern/uipc_socket.c    Tue Mar 23 10:45:37 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uipc_socket.c,v 1.43 1999/01/21 22:09:10 mycroft Exp $ */
+/*     $NetBSD: uipc_socket.c,v 1.44 1999/03/23 10:45:37 lukem Exp $   */
 
 /*
  * Copyright (c) 1982, 1986, 1988, 1990, 1993
@@ -100,6 +100,8 @@
        so->so_proto = prp;
        so->so_send = sosend;
        so->so_receive = soreceive;
+       if (p != 0)
+               so->so_uid = p->p_ucred->cr_uid;
        error = (*prp->pr_usrreq)(so, PRU_ATTACH, (struct mbuf *)0,
            (struct mbuf *)(long)proto, (struct mbuf *)0, p);
        if (error) {
diff -r fd7d8b34272c -r fd1205af3b61 sys/kern/uipc_socket2.c
--- a/sys/kern/uipc_socket2.c   Tue Mar 23 10:22:31 1999 +0000
+++ b/sys/kern/uipc_socket2.c   Tue Mar 23 10:45:37 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uipc_socket2.c,v 1.27 1999/01/20 09:15:41 mycroft Exp $        */
+/*     $NetBSD: uipc_socket2.c,v 1.28 1999/03/23 10:45:37 lukem Exp $  */
 
 /*
  * Copyright (c) 1982, 1986, 1988, 1990, 1993
@@ -174,6 +174,7 @@
        so->so_pgid = head->so_pgid;
        so->so_send = head->so_send;
        so->so_receive = head->so_receive;
+       so->so_uid = head->so_uid;
        (void) soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat);
        soqinsque(head, so, soqueue);
        if ((*so->so_proto->pr_usrreq)(so, PRU_ATTACH,
diff -r fd7d8b34272c -r fd1205af3b61 sys/netinet/in_pcb.c
--- a/sys/netinet/in_pcb.c      Tue Mar 23 10:22:31 1999 +0000
+++ b/sys/netinet/in_pcb.c      Tue Mar 23 10:45:37 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: in_pcb.c,v 1.57 1998/12/19 02:46:12 thorpej Exp $      */
+/*     $NetBSD: in_pcb.c,v 1.58 1999/03/23 10:45:37 lukem Exp $        */
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -219,6 +219,21 @@
                    (p == 0 || (error = suser(p->p_ucred, &p->p_acflag))))
                        return (EACCES);
 #endif
+               if (so->so_uid && !IN_MULTICAST(sin->sin_addr.s_addr)) {
+                       t = in_pcblookup_port(table, sin->sin_addr, lport, 1);
+               /*
+                * XXX: investigate ramifications of loosening this
+                *      restriction so that as long as both ports have
+                *      SO_REUSEPORT allow the bind
+                */
+                       if (t &&
+                           (!in_nullhost(sin->sin_addr) ||
+                            !in_nullhost(t->inp_laddr) ||
+                            (t->inp_socket->so_options & SO_REUSEPORT) == 0)
+                           && (so->so_uid != t->inp_socket->so_uid)) {
+                               return (EADDRINUSE);
+                       }
+               }
                t = in_pcblookup_port(table, sin->sin_addr, lport, wild);
                if (t && (reuseport & t->inp_socket->so_options) == 0)
                        return (EADDRINUSE);
diff -r fd7d8b34272c -r fd1205af3b61 sys/sys/socketvar.h
--- a/sys/sys/socketvar.h       Tue Mar 23 10:22:31 1999 +0000
+++ b/sys/sys/socketvar.h       Tue Mar 23 10:45:37 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: socketvar.h,v 1.36 1999/02/10 14:37:25 tron Exp $      */
+/*     $NetBSD: socketvar.h,v 1.37 1999/03/23 10:45:37 lukem Exp $     */
 
 /*-
  * Copyright (c) 1982, 1986, 1990, 1993
@@ -121,7 +121,7 @@
        int     (*so_receive) __P((struct socket *so, struct mbuf **paddr,
                                   struct uio *uio, struct mbuf **mp0,
                                   struct mbuf **controlp, int *flagsp));
-
+       uid_t   so_uid;                 /* who opened the socket */
 };
 
 /*